Indicator

ABSTRACT

AN INDICATOR UNIT HAVING A LAMP CAPSULE WITH A LEGEND PLATE AND AT LEAST ONE LAMP MOUNTED TO ILLUMINATE THE LEGENED PLATE. A PAIR OF RETAINING ARMS ATTACH THE LAMP CAPSULE TO A TERMINAL BOARD SUCH THAT THE CAPSULE CAN SWING BETWEEN A NORMALLY CLOSED POSITION AND AN EXTENDED POSITION FOR RELAMPING. DETENTS LOCK THE TERMINAL BOARD AND THE LAMP CAPSULE TO THE RETAINING ARMS WHEN THE CAPSULE IS IN THE CLOSED POSITION. A CAM RELEASES THE DETENTS WHEN AN EDGE OF THE LEGEND PLATE IS PUSHED.

United States Patent lnventor Joseph J. Lane Yorba Linda, Calif. Appl. No. 837,629 Filed June 30, i969 Patented June 28, 1971 Assignee Master Specialties Company.

Costa Mesa. Calif.

INDICATOR 4 Claims, 5 Drawing Figs.

US. Cl 40/132, 240/63 int. Cl G09! 13/04 Field oiSearch ..40/l32, 125 (K), 130; 240/63 References Cited I UNITED STATES PATENTS 6/1930 Burke 40/132 2,465,034 3/1949 Peters... 40/l30(UX) 2,925,592 2/1960 Noyes 340/381X 3,034,756 5/1962 KaDell 40/l30X Primary Examiner-Robert W. Michell Assistant Examiner-Richard Carter Attorney-Owen & Owen ABSTRACT:'An indicator unit having a lamp capsule with a legend plate and at least one lamp mounted to illuminate the legend plate. A pair of retaining arms attach the lamp capsule to a terminal board such that the capsule can swing between a normally closed position and an extended position for relamping. Detents lock the terminal board and the lamp capsule to the retaining arms when the capsule is in the closed position. A cam releases the detents when an edge of the legend plate is pushed.

INDICATOR BACKGROUND OF THE INVENTION This invention relates to indicator light units and, more particularly, to an improved indicator light unit having a lamp capsule which may be readily swung from an operating position to an extended position for relamping.

Various types of indicator light units are currently used in annunciator systems for military, aircraft, computer, and industrial uses. Typically, the indicator light units include a lamp capsule mounted in a housing. The lamp capsule includes a translucent legend plate on its front surface and two or more lamps mounted behind the legend plate for illuminating the legend plate. A major, reoccurring problem in the prior art has been to design a suitable indicator unit which permits quick access to the lamps for relamping, while having a maximum sized legend plate and requiring a minimum space behind a panel on which the unit is mounted. The indicator unit should preferably be designed such that a large number may be mounted side-by-side with a minimum spacing between each unit. In one common design suggested in the prior art, the lamp capsule is hinged along one edge to swing out from a housing for relamping. This design however requires a legend plate smaller than the indicator housing dimensions to provide adequate spacing for the hinge and for a locking mechanism which normally holds the lamp capsule within the housing. Furthermore, the space in which the lamp capsule can swing on the hinge for relamping will necessarily be restricted by the hinge. In a second and improved design, the lamp capsule has a generally semicircular cross section. The capsule is mounted to rotate within the housing to expose the lamps for relamping. This design however requires a relatively large spacing for the lamp sockets behind the panel on which the indicator is mounted.

SUMMARY OF THE INVENTION This invention is directed to an indicator unit having a lamp capsule with a legend plate and at least one lamp mounted to illuminate the legend plate. One end of each of a pair of flat, elongated retaining anns is pivotally attached to the capsule and the other end of each arm is pivotally attached to a terminal board, such that the lamp capsule can swing between a nonnally closed position and an extended position for relamping. A pair of cover plates are attached to opposite sides of the terminal board, with a cover plate lying adjacent to each of the retaining arms. The cover plates are spaced to receive at least a portion of the lamp capsule. When the lamp capsule is in the closed position, detents lock the capsule to the retaining arms and the retaining arms to the cover plates. A camming surface is provided between a front edge of a cover plate and a cooperating edge on the lamp capsule for pivoting the lamp capsule to release the detents when an edge of the legend plate is pushed.

The indicator unit is designed for mounting behind an opening ina panel, such as an annunciator panel, with the legend plate lying flush with the panel. The indicator units are designed such that a large number of units may be mounted in a side-by-side relationship with minimum spacing between each adjacent unit. When relamping is necessary, it is only necessary to push along one edge of the legend plate to exert a camming force to tilt the lamp capsule and to then swing the lamp capsule clear of the panel. The instant design allows the lamp capsule to completely clear the front panel, while requiring a minimum mounting space behind the panel.

Accordingly, it is a primary object of the invention to provide an improved indicator .unit which requires minimum mounting space and in which relamping is readily accomplished.

Other objects and advantages of the invention will become apparent from the following detailed description, reference being made to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially exploded perspective view of an indicator unit according to the instant invention;

FIG. 2 is a partially broken away top view of an indicator unit according to the instant invention, with the indicator unit shown mounted behind a panel and with the lamp capsule in the closed position;

FIG. 3 is a partially broken away top view, similar to FIG. 2, but with the lamp capsule in the extended position;

FIG. 4 is a cross-sectional view of the locking detents as taken along line 4-4 of FIG. 2; and

FIG. 5 is a top view of a modified embodiment of an indicator unit according to the instant invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1-4, an indicator unit 10 is shown according to the instant invention. The indicator unit 10 basically comprises a lamp capsule 11 having a legend plate 12, a terminal board 13 and a pair of spaced, flat, elongated, parallel retaining arms 14. The retaining arms 14 are pivotally attached at one end 15 to the lamp capsule 11 by means of a screw or rivet 16. Similarly, the other ends 17 of the retaining arms 14 are attached to the terminal board 13, adjacent an end 18, by means of a screw or rivet 19. When the indicator unit 10 is in its normal or closed position, the retaining arms 14 extend generally diagonally from the end 18 of the terminal board 13 towards an opposed end 20 of the lamp capsule 11.

A pair of cover plates 21 are attached to opposite sides 22 and 23 of the terminal board 13 to cover the retaining arms 14 and a rear portion 24 of the lamp capsule 11 when the lamp capsule 11 is in the closed position. The cover plates 21 are attached to the terminal board 13 by means of a screw or rivet l9 and a second screw or rivet 25.

As shown in FIGS. 1, 2 and 4, each cover plate 21 includes a detent element 26 which projects inwardly towards the lamp capsule 11. The retaining arm 14 includes a cooperating detent element 27 which releasably engages the cover plate detent 26 when the lamp capsule 11 is in the normally closed position. Similarly, the rear portion 24 of the lamp capsule 11 includes a detent element 28 which releasably engages the detent 27 in the retaining arms 14 when the lamp capsule 11 is in the normally closed position. The detents 26, 27 and 28 preferably lie on a centerline through the indicator unit 10.

A pair of lamps 29 are inserted into openings 30 in the rear portion 24 of the lamp capsule 11. Although only a single lamp 29 may be used, it is preferable to have at least two lamps 29 in parallel circuits to provide reliability in the event of failure of one of the lamps. When the lamps 29 are inserted into the rear portion 24 of the capsule 11, they are electrically connected to a common terminal 31. When the lamp capsule 11 is in its nonnally closed position, the lamps 29 and the common terminal 31 are electrically connected to spring terminals 32 mounted on the terminal board 13. a

As shown in FIGS. 2 and 3, the terminal board 13 may be attached to a suitable mount 33 which is attached behind a panel 34 such that, when the lamp capsule 11 is closed, the legend plate is substantially coplanar with the panel 34. A pivot or camming surface 35 projects from an edge 36 of the lamp capsule 11 for engaging a front edge 37 of the cover plates 21. Relamping is accomplished by applying a force F (FIG. 2) adjacent the end 20 of the lamp capsule II. The force F, exerted as by pushing with a finger, causes the lamp capsule 11 to rotate slightly about the cam surface 35, to the position shown in dashed lines in FIG. 2. When the lamp capsule 11 is rotated slightly, an end 38 may be grasped to unlock the detents 26, 27 and 28 and to swing the lamp capsule 11 clear of the panel 34. A notch 39 may be provided in the end 38 to assist in unlocking the detents 26, 27 and 28. The capsule II is shown in an extended position in FIG. 3 with one of the lamps 29 removed for relamping.

Referring now to FIG. 5, a modification of the indicator unit is shown wherein the pivot surface 35 has been eliminated from the lamp capsule ll. The edge 36 extends straight across the lamp capsule II for normally engaging a cooperating flat edge 42 on the cover plates 21. However, in this modification the edge 42 does not extend completely across the front of the cover plates 21, but a portion 43 of the cover plate 21 is cut away adjacent to the end 20 of the lamp capsule 11. The cutaway portion 43 of the cover plate It forms a camming surface for rotating the lamp capsule 11 to disengage the detents 26, 27 and 28 when a force F is applied to the lamp capsule ll adjacent the end 20.

It will be appreciated that the detents 26, 27 and 28 may be modified in obvious manners. For example, the detent 27 in each retaining arm 14 may be simply a hole extending through the retaining arm l4. The detent 26 in the cover plate 21 may be a small protrusion which will then extend inwardly into the hole in the retaining arm 14 while the detent 28 on the lamp capsule 11 will be formed as a small protrusion to project outwardly into the hole in the retaining arm 14 for locking the capsule 11 to the am 14.

lclaim:

1. An indicator unit comprising, in combination, a lamp capsule having a legend plate at its front, means at the back of said capsule for mounting at least one lamp for illuminating said legend plate, a terminal board, a pair of flat elongated retaining arms, means pivotally attaching one end of each of said pair of arms to said terminal board, said arms being parallel to each other, means pivotally attaching the other ends of said arms to opposed sides of said lamp capsule, said lamp capsule swinging with respect to said terminal board between a normally closed position and an extended position for relamping, first locking means for preventing said capsule from pivoting with respect to said arms when said capsule is in the closed position, second locking means for preventing said arms from pivoting with respect to said terminal board when said capsule is in the closed position, and terminal means mounted on said terminal board for electricallyengaging said at least one lamp when said capsule is in the closed position.

2. An indicator unit, as defined in claim 1, and including a pair of spaced cover plates, means attaching said cover plates to said terminal board with said plates being parallel to each other and each plate being adjacent and parallel to a retaining arm, and wherein said first locking means comprises a detent in each of sad retaining arms and means on said capsule for releasably engaging said detents, and said second locking means comprises means on said cover plates for releasably engaging said detents.

3. An indicator unit, as defined in claim 2, and including camming means between said lamp capsule and said cover plates for releasing at least one of said first and second locking means.

4. An indicator unit, as defined in claim 3, and including an indicator panel having an opening adapted to receive said lamp capsule, and means for mounting said terminal board behind said panel with said lamp capsule positioned in said opening and said legend plate flush with said panel. 

